1. Field of the Invention
The invention relates generally to compositions of matter for use in the treatment of malignant tumors.
2. Description of the Related Art
The analgesic effect of snake venoms proteins has been known since antiquity and several authors have pointed out the efficiency of the administration of crude cobra or rattlesnake venoms in the treatment of trigeminal neuralgias, tabetic and pain caused by tumors. In the cases of tumoral pains, the patients could be maintained without the administration of morphine in 70% of the cases. Obviously, at that time crude venoms were employed without even an adequate knowledge of the source. Sometimes the venoms from cobras captured in India or in South Africa were employed indistinctly. However, several reports mentioned besides the analgesic effect, an improvement in the condition of the patients.
Independently, the first cytotoxic component to be isolated and purified to homogeneity from a snake venom was a cytotoxin obtained by BRAGANCA et al. from Naja naja naja venom. Braganca, B. M., Patel, N. T., & Bardinath, P. G., 1967, Biochem., Biophys. Acta, 333-345. TAKECHI et al. isolated two cytotoxins from the same venom having a high cytotoxic activity on tumor cells. Takechi, M., Sasaki, T. & Hayashi, K., 1971, Naturwissenshaften, 58, 323. COTTE et al. showed the cytotoxic effects of Crotalus and Bothrops venoms on several cell lines. Cotte, C. A., Eddenfeld-Yahr, E. and Calvo Lairet A., 1972, Toxicon, 10, 157-163. However, the high concentrations required (100 .mu.g/ml) and the complexity in composition led to the conclusion that the cytotoxic action was a reflection of their non-specific toxic effects. On the other hand, recently, U.S. Pat. No. 4,731,439 and U.S. Pat. No. 4,774,318, issued to Hans Marquardt et al., discloses high cytotoxic activity of polypeptides with low molecular weight (Growth Arresting Peptides, "GAP") isolated from the venom of Crotalus atrox.